1. Field of the Invention
The present invention relates to a wireless communication device communicating data via wireless communication.
2. Description of the Related Art
Within recent advancements in high-speed wireless communication, one technology is known as UWB (Ultra-Wideband). The distinctive features of UWB are short-range high-speed wireless communication and low power consumption. The UWB transfer rate is approximately 10 times greater than the wireless LAN widely used at present, with transmission power on the order of approximately 1/30 that of the wireless LAN.
Given these characteristics, UWB is seen as a means for implementing a so-called home network. For example, wireless USB (Universal Serial Bus) is a standard that is aimed at making wireless the current wire communication standard USB using UWB. In addition since UWB can detect extremely short-duration pulses with high time-accuracy, it has very high ranging accuracy between UWB devices by using the time difference between transmission and reception.
Using wireless communication increases the freedom of connection between devices that hitherto had been connected using a cable or the like, improving user convenience. At the same time, however, with wireless communication, since the connection between devices is invisible it becomes difficult for the user to tell which device is connected with which. In addition, where a plurality of wireless communication devices are present in a range within which wireless communication is possible, although it is possible to use unique parameters such as the IDs or the IP addresses of each device to effect wireless connection, it takes time and effort to input those unique parameters and the input methods are complicated. In particular, when applying this type of wireless connection method to compact devices such as digital cameras, it is necessary to input these unique parameters using only a few small buttons or keys, which adversely affects user operability.
As a result, at present, a technology for effecting wireless connection and disconnection between desired wireless communication devices without a complicated key operation or the like is sought. For example, in Japanese Patent Application Laid-Open No. 2002-118577, a method for effecting a wireless connection by reducing the power of radio waves emitted in an authentication mode as well as confirming entry into a range of radio waves generated by other wireless communication devices either automatically or by the user is proposed.
However, with the method described in Japanese Patent Application Laid-Open No. 2002-118577, where a plurality of other wireless communication devices are within wireless communicable range, it is not easy for the user to know with which device(s) he or she can communicate. In addition, since the range of radio waves used in wireless communication varies depending on usage conditions and the location of the devices, the user cannot know with certainty the device(s) with which connection has been established.